[PATCH v2 4/4] dmaengine: rcar-dmac: Add support for R-Car V3U

Geert Uytterhoeven
2021-01-26T21:28:21Z

The DMACs (both SYS-DMAC and RT-DMAC) on R-Car V3U differ slightly from
the DMACs on R-Car Gen2 and other R-Car Gen3 SoCs:
1. The per-channel registers are located in a second register block.
Add support for mapping the second block, using the appropriate
offsets and stride.
2. The common Channel Clear Register (DMACHCLR) was replaced by a
per-channel register.
Update rcar_dmac_chan_clear{,_all}() to handle this.
As rcar_dmac_init() needs to clear the status before the individual
channels are probed, channel index and base address initialization
are moved forward.

Inspired by a patch in the BSP by Phong Hoang
<phong.hoang.wz@renesas.com>.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
v2:
- Use two separate named regions instead of an iomem[] array,
- Drop rcar_dmac_of_data.chan_reg_block, check for
!rcar_dmac_of_data.chan_offset_base instead,
- Precalculate chan_base in rcar_dmac_probe().
---
drivers/dma/sh/rcar-dmac.c | 74 ++++++++++++++++++++++++++++----------
1 file changed, 55 insertions(+), 19 deletions(-)

diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
index 7a0f802c61e5152d..d9589eea98083215 100644
--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -189,7 +189,8 @@ struct rcar_dmac_chan {
* struct rcar_dmac - R-Car Gen2 DMA Controller
* @engine: base DMA engine object
* @dev: the hardware device
- * @iomem: remapped I/O memory base
+ * @dmac_base: remapped base register block
+ * @chan_base: remapped channel register block (optional)
* @n_channels: number of available channels
* @channels: array of DMAC channels
* @channels_mask: bitfield of which DMA channels are managed by this driver
@@ -198,7 +199,8 @@ struct rcar_dmac_chan {
struct rcar_dmac {
struct dma_device engine;
struct device *dev;
- void __iomem *iomem;
+ void __iomem *dmac_base;
+ void __iomem *chan_base;

unsigned int n_channels;
struct rcar_dmac_chan *channels;
@@ -234,7 +236,7 @@ struct rcar_dmac_of_data {
#define RCAR_DMAOR_PRI_ROUND_ROBIN (3 << 8)
#define RCAR_DMAOR_AE (1 << 2)
#define RCAR_DMAOR_DME (1 << 0)
-#define RCAR_DMACHCLR 0x0080
+#define RCAR_DMACHCLR 0x0080 /* Not on R-Car V3U */
#define RCAR_DMADPSEC 0x00a0

#define RCAR_DMASAR 0x0000
@@ -297,6 +299,9 @@ struct rcar_dmac_of_data {
#define RCAR_DMAFIXDAR 0x0014
#define RCAR_DMAFIXDPBASE 0x0060

+/* For R-Car V3U */
+#define RCAR_V3U_DMACHCLR 0x0100
+
/* Hardcode the MEMCPY transfer size to 4 bytes. */
#define RCAR_DMAC_MEMCPY_XFER_SIZE 4

@@ -307,17 +312,17 @@ struct rcar_dmac_of_data {
static void rcar_dmac_write(struct rcar_dmac *dmac, u32 reg, u32 data)
{
if (reg == RCAR_DMAOR)
- writew(data, dmac->iomem + reg);
+ writew(data, dmac->dmac_base + reg);
else
- writel(data, dmac->iomem + reg);
+ writel(data, dmac->dmac_base + reg);
}

static u32 rcar_dmac_read(struct rcar_dmac *dmac, u32 reg)
{
if (reg == RCAR_DMAOR)
- return readw(dmac->iomem + reg);
+ return readw(dmac->dmac_base + reg);
else
- return readl(dmac->iomem + reg);
+ return readl(dmac->dmac_base + reg);
}

static u32 rcar_dmac_chan_read(struct rcar_dmac_chan *chan, u32 reg)
@@ -339,12 +344,23 @@ static void rcar_dmac_chan_write(struct rcar_dmac_chan *chan, u32 reg, u32 data)
static void rcar_dmac_chan_clear(struct rcar_dmac *dmac,
struct rcar_dmac_chan *chan)
{
- rcar_dmac_write(dmac, RCAR_DMACHCLR, BIT(chan->index));
+ if (dmac->chan_base)
+ rcar_dmac_chan_write(chan, RCAR_V3U_DMACHCLR, 1);
+ else
+ rcar_dmac_write(dmac, RCAR_DMACHCLR, BIT(chan->index));
}

static void rcar_dmac_chan_clear_all(struct rcar_dmac *dmac)
{
- rcar_dmac_write(dmac, RCAR_DMACHCLR, dmac->channels_mask);
+ struct rcar_dmac_chan *chan;
+ unsigned int i;
+
+ if (dmac->chan_base) {
+ for_each_rcar_dmac_chan(i, chan, dmac)
+ rcar_dmac_chan_write(chan, RCAR_V3U_DMACHCLR, 1);
+ } else {
+ rcar_dmac_write(dmac, RCAR_DMACHCLR, dmac->channels_mask);
+ }
}

/* -----------------------------------------------------------------------------
@@ -1744,7 +1760,6 @@ static const struct dev_pm_ops rcar_dmac_pm = {

static int rcar_dmac_chan_probe(struct rcar_dmac *dmac,
struct rcar_dmac_chan *rchan,
- const struct rcar_dmac_of_data *data,
unsigned int index)
{
struct platform_device *pdev = to_platform_device(dmac->dev);
@@ -1753,9 +1768,6 @@ static int rcar_dmac_chan_probe(struct rcar_dmac *dmac,
char *irqname;
int ret;

- rchan->index = index;
- rchan->iomem = dmac->iomem + data->chan_offset_base +
- data->chan_offset_stride * index;
rchan->mid_rid = -EINVAL;

spin_lock_init(&rchan->lock);
@@ -1842,6 +1854,7 @@ static int rcar_dmac_probe(struct platform_device *pdev)
const struct rcar_dmac_of_data *data;
struct rcar_dmac_chan *chan;
struct dma_device *engine;
+ void __iomem *chan_base;
struct rcar_dmac *dmac;
unsigned int i;
int ret;
@@ -1880,9 +1893,24 @@ static int rcar_dmac_probe(struct platform_device *pdev)
return -ENOMEM;

/* Request resources. */
- dmac->iomem = devm_platform_ioremap_resource(pdev, 0);
- if (IS_ERR(dmac->iomem))
- return PTR_ERR(dmac->iomem);
+ dmac->dmac_base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(dmac->dmac_base))
+ return PTR_ERR(dmac->dmac_base);
+
+ if (!data->chan_offset_base) {
+ dmac->chan_base = devm_platform_ioremap_resource(pdev, 1);
+ if (IS_ERR(dmac->chan_base))
+ return PTR_ERR(dmac->chan_base);
+
+ chan_base = dmac->chan_base;
+ } else {
+ chan_base = dmac->dmac_base + data->chan_offset_base;
+ }
+
+ for_each_rcar_dmac_chan(i, chan, dmac) {
+ chan->index = i;
+ chan->iomem = chan_base + i * data->chan_offset_stride;
+ }

/* Enable runtime PM and initialize the device. */
pm_runtime_enable(&pdev->dev);
@@ -1929,7 +1957,7 @@ static int rcar_dmac_probe(struct platform_device *pdev)
INIT_LIST_HEAD(&engine->channels);

for_each_rcar_dmac_chan(i, chan, dmac) {
- ret = rcar_dmac_chan_probe(dmac, chan, data, i);
+ ret = rcar_dmac_chan_probe(dmac, chan, i);
if (ret < 0)
goto error;
}
@@ -1977,14 +2005,22 @@ static void rcar_dmac_shutdown(struct platform_device *pdev)
}

static const struct rcar_dmac_of_data rcar_dmac_data = {
- .chan_offset_base = 0x8000,
- .chan_offset_stride = 0x80,
+ .chan_offset_base = 0x8000,
+ .chan_offset_stride = 0x80,
+};
+
+static const struct rcar_dmac_of_data rcar_v3u_dmac_data = {
+ .chan_offset_base = 0x0,
+ .chan_offset_stride = 0x1000,
};

static const struct of_device_id rcar_dmac_of_ids[] = {
{
.compatible = "renesas,rcar-dmac",
.data = &rcar_dmac_data,
+ }, {
+ .compatible = "renesas,dmac-r8a779a0",
+ .data = &rcar_v3u_dmac_data,
},
{ /* Sentinel */ }
};
--
2.25.1